广东省稻瘟病菌群体交配型及育性的比较研究

Mating Type and Fertility of the Rice Blast Fungus Population Derived from Guangdong Province, China

以分离自泰国大麦稻瘟病菌的2 个菌株TH12 和TH16,以及中国云南旱稻稻瘟病菌的2 个菌株94-64-1b和95-23-4a 为A、B 两组标准菌株;以采集于2002 年度广东省三大稻作区的141 个稻瘟病菌株为供试菌株;对广东省稻瘟病菌群体的交配型及育性结构,以及两对标准菌株的鉴别能力进行了分析。在育性方面,广东群体的可育性菌株平均频率为85.9%。其中,粤北稻作区的最高,为97.7%,粤南稻作区的次之,为85.5%,粤中稻作区的最低,为74.2%。由此说明,稻作区之间存在一定的差异。就生长季节而言,早季的可育性菌株频率为82.8%,晚季的为89.6%,两者的差异不大。在交配型结构方面,广东群体以MAT1-2 型菌株占绝对优势,占全部可育性菌株的98.3%。还有,在菌株的性别方面,广东群体的可育性菌株皆为雄性,而没有雌性和两性菌株。另一方面,在广东群体中,A 组标准菌株的交配型检出率为86.5%,而B 组标准菌株的交配型检出率仅为4.3%。由此说明, A组标准菌株的交配型鉴别能力远比B 组标准菌株的强。这些结果提示,在进行交配型测定时,标准菌株的遗传背景和配合能力是应该考虑的重要因素。

Mating type and fertility of rice blast fungus population, which consists of 141 isolates collected from Guangdong (GD) Province, China, were characterized by using A and B sets of standard isolates originated from barley and rice, respectively. As for fertility, the frequencies of fertile isolates were 97.7%, 74.2% and 85.5%, respectively, in North, Middle and South GD regions. As for rice-growing season, the frequencies of fertile isolates were 82.8% and 89.6% in early and late seasons respectively. As for mating type, GD population was predominated of MAT1-2. That is, the proportion of MAT1-2 isolates in the fertile part was 98.3%. As for the sexes of isolates, all the fertile isolates were male isolates. In other words, there is no any female and hermaphroditic isolate in the GD population. In regard to the two sets of standard isolates, the frequencies of mating type identified were 86.5% and 4.3% in the GD population by A and B sets, respectively, suggesting that the differentiating capacities of A and B sets of standard isolates are quite different. This result further suggests the genetic background and/or combining ability of standard isolates are important factors in determining mating types and fertilities of heterothalic isolates.